But Saturday, he left the track in a completely different mood, as he and Billy Johnson won their second Grand Sport (GS) race together, the two-and-a-half hour, 91-lap Homestead 200, in the No. 61 ROUSH Performance Products Ford Mustang GT.
For Johnson, it was his second consecutive victory at the 2.3-mile, 11-turn road course, in a car that advanced 33 positions from start to finish.
Roush originally set a track record Friday but his time was disallowed following post-qualifying technical inspection, an unapproved part to blame. But that didn't deter Roush, who was among the fastest in every session during the weekend. Starting 34th, he passed 10 cars on the first lap and was up to 21st after two laps. He finally took the lead on Lap 35.
Johnson took over on Lap 39, and kept the duo among the top five and eventually into second as late as the final half hour. That's when Johnson was attempting to catch Matt Plumb, co-winner of this season's opening race at Daytona.
Plumb took over from Miami native Gian Bacardi during the race's first caution period, around the 30-minute mark, and pitted again with enough fuel and solid tires to go the remainder of the race. But with 20 minutes remaining, he went from leading to retired.
Driving the No. 13 RumBum.com BMW M3, Plumb hit the rear of Eric Curran's No. 46 Fall-Line Motorsports BMW M3 in Turn 1, as Curran got bottled up behind slower traffic. The impact forced the hood of the No. 13 to come up, and Plumb in a precarious position, driving cautiously around the track with his windshield covered.
Plumb managed to make it to the final turn before hitting barrels filled with sand at the pit entrance. The sand and debris from the barrels forced the final of four caution periods, and put Johnson in front. He never looked back when the green flag flew on Lap 87, and charged to a 2.561-second victory.
It marked Johnson's seventh series victory and third in the Grand Sport class. "Jack did have quite a bit of fun today," said Johnson, who led twice for nine laps. "He did an amazing job in qualifying. He went through the entire field today, which is no easy feat with the caliber of drivers at this track. He handled it like a pro. He kept the fenders clean and just moved through everyone. He turned the car over in one piece for, gave us good track position and I took it from there. I had to work through a few people myself, but I was able to come out on top again."
For Roush Jr., who celebrated with his father, Jack Roush Sr., in Victory Lane, it was a complete turnaround of emotions from close to 24 hours earlier.
"It was real exciting race for us," Roush Jr. said. "I can't be more proud of my team and all the work they've done. It was a real privilege to be part of history with the Roush Racing group. I also have to hand it to my co-driver, Billy Johnson. He did an awesome job today. I'm looking forward to many more races."
The win was also Roush Sr.'s 400th as a car owner. In nearly 40 years as an owner, Roush Sr. has also won in NASCAR's three National series, Trans-Am and IMSA.
The next race for the Continental Tire Sports Car Challenge will be April 10 at Barber Motorsports Park in Birmingham, Ala.